Abstract

Block copolymers have gained increasing scientific attention since their successful synthesis by homogeneous anionic polymerization in 1956d). Interest was heightened by the possibility that block copolymers might be materials possessing desirable properties, a possibility originally considered by Mark(2). One important class of block copolymers are the polystyrene-polybutadiene-polystyrene block copolymers (S-B-S) introduced by the Shell Chemical Company (U.S.A.) in 1965(3). Electron microscope studies by Meieron styrene-isoprene two block model and studies by Hendus, Illers, and Ropte(S) on polystyrene-polybutadiene block copolymers showed that under certain conditions of preparation the styrene exists in glassy domains interconnected by amorphous polybutadiene regions. Furthermore, Hendus, et al., showed that the size of the polystyrene domains and the morphology of the films is dependent on composition and molecular weight of the copolymer. Also, the domains of the polymers were found to be altered by the solvent from which the copolymer films were cast(6).